I have a Panasonic plasma and it looks stunning on my 722k, especially after I tweaked the settings on the Panasonic.
As to 1080p, well if you've been reading here, there is damned little of that via sattelite other than PPV.
Something to check is what is doing the conversion to 1080p? Your plasma is 1080p and that is the only actual res it shows, either by the TV doing the conversion, or your AV doing it. Try to see if you can set your AV to do the conversion, or if it already is, change that to not convert and let the TV do it.
Then go look at AVSForums in the plasma forums and see if someone has offsets made for your particular model. Mine was there and it made a huge difference in quality of picture from all sources.